I. Field of Use
The present application relates to the field of home security. More specifically, the present application relates to door and window sensors typically used in home and businesses.
II. Description of the Related Art
Security systems for homes and offices have been around for many years. Often, these systems make use of door and window sensors installed onto some or all of the doors and windows found in a structure. These sensors typically comprise two distinct parts: a magnet and a reed switch. The magnet is typically installed onto a movable part of a window or onto a door edge, while the detector is mounted to a stationary surface, such as a door or window frame. When the door or window is closed, the magnet and reed switch are in close proximity to one another, maintaining the reed switch in a first state indicative of a “no alarm” condition. If the door or window is opened, proximity is lost between the magnet and the reed switch, resulting in the reed switch changing state, e.g., from closed to open or from open to closed. The change of state is indicative of an alarm condition, and a signal may be generated by circuitry associated with the reed switch and sent, via wires or over-the-air, to a central processing station, either in the home or at a remote monitoring station. Alternatively, or in addition, a loud audible alert is generated, either at the central processing station in the home or directly by the circuitry associated with the reed switch, indicating that a door or window has been opened without authorization.
One of the disadvantages of typical door and window alarms is that they do not allow for conditions other than “door/window open” and “door/window closed”. For example, one might like to open a window a few inches to let air inside a home, but also to be alerted if the window were to be opened further than the initial position set by the homeowner.
Another disadvantage of present door and window alarms is the inflexibility of these prior art alarm devices to detect anything other than a door/window open or door/window closed state.
Thus, it would be desirable to provide a security sensor that allows more flexibility than present door and window sensors to determine when a true alarm condition has been triggered, while additionally allowing a door or window to be opened slightly without triggering an alarm event.